refactor for scikit-learn renaming
Merge pull request #1 from buhman/master

scikit-learn >= 0.12 refactoring
Merge remote-tracking branch 'upstream/master'

Conflicts:
	src/python/borg/experimental.py
	src/python/borg/models.pyx
	src/python/borg/portfolios.py
	src/python/borg/wscript
Merge branch 'master' into features/pypi